I'm Pretty Sure It's Not A Baby But It Feels Like One?

ive been having these weird feelings like someones touching my c section scar on the inside... i've googled my symptoms and everyone says its gas but they're explaining a feeling up higher closer to their ribs. im on depo so i don't get real periods and it feels like a 5 month old baby in there. i don't think im pregnant but i wouldn't know since im still nursing and not having regular periods... i also get really bad pains on my right side i think that's an ulcer though... im really worried cuz i haven't had sex in like over a month or two and i took a pregnancy test when i got my last depo shot. what could this be???